Analogue regenerative transponders including regenerative transponder systems

ABSTRACT

In a transponder ( 19 ) for amplification of a received signal ( 60 ) into an antenna ( 1 ), to a signal ( 61 ) for retransmission, and where the retransmitted signal ( 61 ) possibly may have information superimposed, a quenched oscillator ( 5 ) is incorporated as amplifying element. The oscillator ( 5 ) is preferably of superregenerative type and exhibits negative resistance ( 30 ) for the received signal ( 60 ). Transponders according to the present invention may be introduced as system elements in a wireless or wire based network to work as intelligent or unintelligent connections in the network. The transponders can also be used in positioning systems.

INTRODUCTION

The present invention concerns transponders of the general type asexplained in the preamble of the appended claim 1, the application ofsuch transponders in networks, as well as transponder systems innetworks as given in the preamble of the appended claim 33.

BACKGROUND

In a transponder system a radio frequency signal is transmitted to atransponder, which in turn retransmits the signal, often in modulatedform, that is to say with superimposed information from the transponder.The purpose of a transponder may thereby be to convey or retrieveinformation related to the transponder in some way. Transpondersnormally are not expected to relay the incoming signal only with theoriginal information. Some transponders work indirectly, othersdirectly. In indirect retransmission, the signal is received andretransmitted in sequence. Retransmission may be desired to take placein a frequency band different from the band for received signal. Moderndigital communication transponders, also named repeaters are known todigitally process the signal in then retransmit the information. Thisknown technology works at the expense of complexity, cost and reducedinformation bandwidth.

Modern digital data communication has put forward a tremendous need forexpanded and improved infrastructure in two-way access networks (lastmile). It is partly true for long range (long haul) communication (firstmile) as well. In satellite access networks there has been a continuedsearch for inexpensive return channel capacity which, until now to alarge degree has relied upon phone copper networks.

Recent years innovations of extending communication range, bandwidth andreliability has mostly dealt with novel applications of digital signalprocessing as well as improved approaches hereof. It seems forgotten orneglected that the analogue signal processing is and always will be thebasic physical layer of any communication or transmission system.Despite all improvements in digital signal processing, the attainableresults will always be ultimately limited by the analogue signalprocessing parameters. It may be concluded that vast improvements andnew eras of the overall signal processing could be achieved if theanalogue signal processing was paid equal attention.

In wireless applications, the path loss may vary typically from 80 to130 dB.

In cable and wire bound applications the losses when trying to usehigher frequency bands may vary typically from 30 to 80 dB. At the sametime, isolation between circuits that are not optimally separated byintrinsic or introduced properties is only typically from 0 to 15 dB.

Without exceptions, modern transponders or repeaters for high frequencycarrier digital transmission therefore do not utilise high, in-band oradjacent channel analogue in line gains. This type of duplex signalrepetition will in most systems lead to instability and therefore cannotbe realised using conventional technology. Textbooks therefore have nosolutions for this type of problem. A typical modern problem of thiskind is the up- and downstream amplification in Cable Modem systems.Here the problem is passing two signal directions through one coaxialcable and amplifying the signals at certain intervals. The solution tothe problem using known technology is the so called bidirectionalamplifiers that simply are one amplifier for one direction combined witha bypass filter for the other. The solution depends upon the frequencydifference of the two signal directions being large to optimizestability resulting from the limited isolation between the two mainports of the device. In other cable and wire based applications theresimply are no analogue gain solutions when high isolation between portscannot be realised from one reason or the other. A typical example is apower circuit grid connection box where connections must enter and leavethe power rails directly and thereby inhibit acceptable amplifier portisolation. Similarly, in power grid transformer stations, signal leakagevia the low voltage circuits, the transformer and the medium voltagecircuits prevent acceptable isolation. That is why all PLC (Power LineCommunication) systems for internet access up till now do not usedistributed analogue gain blocks to preserve signal to noise ratio.Distributed, cascaded gain blocks are fundamental in Cable Modem systemsusing low loss coaxial cables. In power grids with substantially higherattenuation, the need for corresponding gain blocks is no less and thetechnical challenges are in most respects substantially greater. Usinganalogue gain blocks in the power grid which also can be cascadedevidently was not thought of as realistic and practicable in PLCsystems. The serious set-backs PLC access systems have suffered from theinability to produce reliable, large bandwidths and to comply withregulations demonstrate this. Known PLC access systems all useproprietary, switched symmetrical communication protocols. That impliesalso a further challenge to conventional gain blocks in that the gainblock must be bi-directional. This has forced the PLC system designersto either use digital repeaters that reduce bandwidth or to useexcessive excitation levels as well as relatively low carrierfrequencies to obtain desired communication range. The switching natureof the signals just makes the emission problem more serious. Long delaytimes are also a typical disadvantage of these systems, making them lessapplicable to time critical applications, like IP telephony. This willespecially be true for large systems with a high number of clients. PLCsystems are characterized by the lack of ability to use as high acarrier frequency as the infrastructure will allow to improve emissionand immunity characteristics, to enjoy the benefits of dampedreflections and to reduce the in band group delay ripple. The lower thefrequency used is in a PLC system, the more transfer characteristicswill vary. These reasons combined can be thought of as the technicalexplanation why PLC access systems is so far did not gain noticeable useover the past 5 to 10 years.

In wireless systems, the situation is similar using symmetrically,switched systems requiring in-band bidirectional transponders orrepeaters. With two or more antennas, a certain gain can be achieved.However, this gain is usually not nearly sufficient to compensate forlosses plus achieve the required net gain. This is why modem uses havefound no other way of solving related data transmission transponder orrepeater problems than using technologies that reduce bandwidth and addhigh cost. The need for new core as well as system technologies thatallow inexpensive and simple analogue high cascaded high frequency gainswhere high port isolation shows impractical is present in a large numberof digital as well as analogue communication areas.

It has been shown that transponders may be realised as simple, injectionlocked oscillators. The use of these transponders has up till now beenlimited to obtaining a transponder modulation response, not to repeat asignal. The largest disadvantage of the injection locked oscillator is avery narrow lock frequency band and a very low sensitivity. There is aneed for a technology, which improves the injection locked oscillatorand expands the applications there of.

During the years that followed Fleming's invention of the vacuum tubeand Armstrong's invention of the super regenerative detector, variousattempts were made to utilise the technology in signalling networks.Some of them were patented. Most of them are characterised by using theregenerative circuits only for reception, some for obtaining modulatedtransponder responses as well. That includes some fairly recent patentsbased on solid state components. Very few may have proposed signalrepetition or cascaded regenerative gain in which cases the describeduses are outdated or very narrow, too limited for todays needs orcontains serious discrepancies between the suggested solutions and someof the proposed uses. Common to all of them is at any rate the use ofvacuum tube and not solid state gain elements. The use of vacuum tubesalso prevented the technologies to prove reliable in field uses.Furthermore, using vacuum tubes limited or prevented the necessaryrefinement, repeatability, reliability and acceptable costs. Common toall of them are narrow credible communication bandwidths, and the lackof sharp band pass filtering of both input and output signals to meettoday's standards for immunity and unwanted emission. Since then, thetechnologies have been forgotten or neglected. The industry has failedto acknowledge that modern solid state components with vastly improvedspecifications and cost factors could put Armstrong's invention in acompletely new light. All this shows that there is an unsolved need fornovel analogue gain block solutions in modern digital communication. Italso shows that neglected and forgotten technology by novel applicationsand by using novel architectures based on modern component technologymay contribute to meet this need.

In power line surveillance and communication (PLC) on the distributioncircuits, where data communication is to include so called accessnetworks for broad band distribution and other communication withclients, the communication range up till now would be limited to 100 to300 meters due to signal losses. At these limiting distances unwantedemission could still pose serious problems. Line amplifiers are veryexpensive to realise and install and indirect repeaters reduce the databandwidth. This is also true for high voltage cables where up till nowonly systems with extremely narrow bandwidths have been commerciallyavailable. Consequently known technology was limited to small systemsthat had to be linked by optical, copper, satellite or wirelesscommunication. It is therefore a need for a novel technology which willallow the complete infrastructure of power grid networks to be tiedtogether as cable or wire communication networks. With known technologythere exists no solution, which in a simple, reliable, repeatable andinexpensive way can relay signals without complex arrangements passedembedded separations in a power network, i.e. a transformer station ordistribution panels. There is a need for novel solutions that can bothdeliver analogue gain and bridge between parts of power grid structures.Existing systems for large bandwidth communication on power lines usethe lower part of the RF spectrum to achieve acceptable attenuationlevels and therefore suffer severe penalties from low frequency noiseand variations that is significant on low voltage lines up to 20 MHz andin some parts of the power grid considerably higher. Power line noiseexhibits both systematic and white noise characteristics, making theefficiency of various spread spectrum technologies variable andsometimes unpredictable. Typical of a power grid with a number ofdifferent circuits is that the lower region high frequencycharacteristics will vary tremendously, geographically and by time. PLCdesigners then, also were forced to use high signal excitation powerlevels causing unacceptable radiated levels. It exists therefore a needfor a novel technology for analogue gain blocks in electricity networksused as access data networks employing simple methods requiring small orno modification of the infrastructure. Such technology would beapplicable to medium and high voltage systems as well and can have largeimplications in wireless analogue and digital communication andbroadcasting.

SUMMARY OF THE INVENTION

It is therefore a main object of the present invention to providetransponders, repeaters and transponder or repeater systems, couplingarrangements, intercoupling arrangements as well as improvements thereofthat facilitate substantial high frequency analogue cascaded gain toexisting and new systems and infrastructure used or useful forcommunication where traditionally acceptable port isolation isimpractical or intrinsically prevented. The object of the invention isalso is to allow bidirectional gains, either in-band or in separatefrequency bands for numerous high frequency applications. It is thus asignificant object of the invention is to provide novel solutions thatwill improve existing communication infrastructure or facilitatecommunication using infrastructure that otherwise was not intended foruse as communication infrastructure.

It follows that an objective of the present invention is to provide avery universal and at the same time inexpensive system for repeating RFsignals, on a single or cascaded basis. This is realised through asingle or a number of regenerative transponders or repeaters andcoupling arrangements that are easy to install and power, and thatrequire minor or no modification to the infrastructure and whichtherefore will meet requirements when the infrastructure by any reasoncannot be substantially modified. It is thus an objective of theinvention to facilitate long communication ranges and bandwidth wherethis would otherwise be impossible, impracticable or too expensive.

Another object of the invention is also to provide means of realisingnew types of communication systems based on the simplicity and highperformance of the present invention that otherwise would not bepossible or would be too costly to realise.

It is yet another object of the present invention to provide cascadedsystem regenerative gain blocks for unidirectional, bidirectional andmultidirectional uses.

Another object of the present invention is to function both whenfrequency bands for up link and down link are overlapping as well aswhen they are separated or adjacent. It is further an object of thepresent invention that it should function both when signal dynamics uplink and down link and in different directions are similar and when theyare significantly different.

A further object of the present invention is to facilitateinterconnections between transmission media and analogue systemcomponents. Also an object of the invention is to facilitate extensionsof coaxial cable systems, fibre cable systems and hybrid fibre andcoaxial systems (HFC) to the power line grids or other infrastructuresavailable that resemble transmission mediums.

It is thus an object of the invention to facilitate new or improveexisting RF signal paths for any existing communications or broadcastsystem. Examples hereof are the use of cable modem or long rangeEthernet technology on power line grids including high voltage, mediumvoltage, low voltage, street lighting and control cables and wires. Onemore example of application of the invention is extending wireless LANcommunication range or the similar.

It is also an object of the invention to provide some novel improved oralternative transponder solutions to radio navigation, radiopositioning, radio direction finding, radio ranging, RFID and ECM usesas well

THE INVENTION

Several of the objects of the invention are achieved, in a first aspect,with a transponder as given in the appended claim 1. Further,advantageous characteristics are given by the attached dependent claims.

Further stated objects, are achieved in a second aspect, with atransponder system as given in the appended claim 33.

Further characteristics of the system are given by the dependent,attached claims.

Completely independent of the way the first aspect of the invention isrealised in detail, the principle of the invention may be described as aregenerative gain block, possibly of the super regenerative type, and isoften preferred as a one port with negative resistance. Technicallyidentical or similar to a quenched oscillator in the invention is aquenched or switched amplifier since stability criteria will not only bedetermined by internal characteristics but by the external parameters aswell. A quenched amplifier as such therefore by definition is a quenchedoscillator.

An evident characteristic of the invention are simple transponders thatexhibit high conversion gain, and the transponder with correspondingperformance may retransmit an amplified version of a received signal inthe same frequency band or in a frequency shifted band and may work as aone-port amplifier and thus may be used to work directly in anuninterrupted signal path. It is thus well suited for sustaining thesignal to noise ratio on a transmission line like a power cable withoutexceeding critical radiation levels. Advantages of the quenchedoscillator transponder of the invention are the choices available tocustomise dynamic range and bandwidths. An example is using the wholebandwidth energy or all the useful sidebands which also adds redundancy.Another example is using a sideband or several sidebands selectivelyaided by filtering. An evident characteristic of the invention whenusing the super regenerative principle is the use of sharp band passfilters for output and input to aid modern requirements for immunity andunwanted emissions and wide communication bandwidth properties that maybe aided by high quench frequencies. This requires fairly advancedfilter designs where the highest attention must be paid to both the passband transfer characteristics as well as the out of band transfercharacteristics. This is important due to the high in band (channel) andadjacent band (channel) gains required.

The invention may be characterised by stray capacitance in componentsand structures often being a satisfactory link of the coupling oftransponders in the invention and this is aided by the inventionallowing higher frequencies used which increases the efficiency of straycouplings. In short, the large amplification associated with the presentinvention facilitates coupling arrangements otherwise inconceivable fortechnical or economical reasons. One example of such facilitation by theinvention is in medium voltage installations is using the capacitivevoltage probe of “Elastimold” power net stations and cable connectionsfor signal transfers with high frequency carriers. Cables associatedwith Elastimold and subsequent systems may be called Pex cables and theyresemble a coaxial cable structure with one or more inner conductor andan outer shield. The capacitive divider of the Elastimold and similarsystems will show increased efficiency with frequency. The capacitivedivider probe will often suffice as the RF signal sensor, but may beinefficient for excitation. An improved version of the capacitivedivider coupling of the invention emerges when the outer shield is usedas the coupling capacitor. This is further improved in the invention ifa ferrite or iron powder sleeve or toroid core is clamped on the cableat a certain distance from the cable termination. Similarly in theinvention, stray capacitance between the inner conductor and the commonpotential may be utilised as a coupling capacitor allowing the couplingof signals between the shield and the common potential. The inventionmay use a designated stray capacitor arrangement to achieve an efficientcommon high frequency potential and thus also aid suppression ofunwanted common mode emission and immunity. The invention may utilisethe RF signal being injected or sampled in a differential fashion usingat least two cables or with ground as reference or a combination of thetwo.

The present invention therefore allows higher carrier frequencies to beused in power grid circuits than so called PLC (Power LineCommunication) systems. By utilising the radiation loss for both thesystem energy on the cable and the RF interference signals picked up bythe cable in combination with high carrier frequencies well away frompower line noise, very low signal levels are required and the risk ofdisturbing other services is eliminated. RF interference on highercarrier frequencies can be minimised using redundancy in the frequencydomain. The present invention allows for a large number of combinationsto provide redundancy when it is required, i.e. on low voltage powerlines in homes and buildings where the power line noise problem issignificant. Redundancy can also be added in order to increase totalsystem bandwidth by i.e. adding more communication channels. A furtherutilisation of redundancy may be accomplished by remotely orautomatically controlling or switching properties of transponders orrepeaters in the communication system for system adaptability toenvironment changes like i.e. interference.

The invention may utilise the frequency shifting or transposingcharacteristics of the super regenerative repeater (transponder) alongwith its high conversion gain. The frequency shift may then be equal toor a multiple of the quench frequency to either side of the centrefrequency. Similarly, another novel solution of the invention usingtraditional but more costly and power consuming technology using afrequency converter or mixer in series with an amplifier where input andoutput of the mixer—amplifier chain is tied together and used as aone-port or where isolation between them is intrinsically seriouslylimited. The application hereof may be in cable or wire systems toincrease noise tolerance, adaptation to varying cable types, lengths andlosses using one-port or limited two-port amplification including afrequency shift. The principal function of both these implementations isidentical and can be described as a frequency transposing one-portamplifier. The practical difference between them is that the superregenerative solution of the invention is independent upon adjacentchannel selectivity whereas the mixer solution of the invention doesrequire good filtering. These are important considerations when usefulor available frequency bands are restricted.

Another characteristic of the invention is an improvement of theregenerative and super regenerative oscillator or amplifier combinedwith a bidirectional super heterodyne signal block. It consists of oneor more frequency mixers with a common local oscillator. It may containgain stages for both directions, the purpose being to compensate forlosses and to assist obtaining the signal dynamics of the transponder.It allows the regenerative oscillator to be optimized in a frequencyband different to the transponder frequency band, for example withrespect to using a very high quench frequency for large transponderbandwidths. It may allow the transponder frequency band of the inventionto be easily changed by altering the local oscillator frequency. It maycontain filters on both the transponder frequency band of the inventionand the regenerative device frequency band. It also increases dynamicrange because quench frequency harmonics suppression is improved. It mayalso contain directional combiners to increase the allowable gain in thesuper heterodyne block. The super heterodyne net gain may be achieved byactive mixers. When appreciable external port isolation is present, thetransponder may be used as a two port separating the heterodyne gain foreach direction. Unidirectional system gain, as with asymmetricalsystems, may be served this way. Up and down links may be combined withdual or two transponders according to the invention. Yet another novelcharacteristic of the invention is when moderate high frequency gain isrequired. Then inherent added isolation by the mixers in the inventionallows the regenerative oscillator to be omitted, thus byinterconnecting the super heterodyne chains the super heterodyne gainitself will allow sufficient regeneration.

The super regenerative oscillator in the present invention works in away so that without signal, during one quench cycle, it does not reachfull oscillation conditions. The regeneration range is determined mainlyby the bias conditions and the quenching function. The most significantproperty of the quenching function is the quench frequency. At sub Hertzfrequency (1/f), regeneration is moderate and has poorer selfstabilisation. At very high quench frequency gain will deteriorate whilestability remains good. At medium quenching frequencies, gain is highand stability is good, but bandwidth properties may not be useful. Thepresent invention facilitates an optimum combination of these factors.The possibility of using higher carrier frequencies on longer, highcurrent and high voltage shielded power cables is also facilitated bythe present invention. The advantage here being avoidance of lowfrequency region noise as well as reduced group delay ripple within thecommunication band. Less variations in transfer characteristic is one ofthe great advantages of being able to use as high carrier frequencies aspossible on both large and small size power cables. The inventionfacilitates this in many ways; one is large available amplificationgains and the implicit possibility of introducing gains in uninterruptedcircuits as well as non-galvanic couplings. Even cancellation of freespace noise and unwanted radiation on power cable communication systemsis part of the present invention. Perhaps the most interesting aspect ofthe invention is that all implementations allow low cost systemrealisations.

The facilitation for communication networks generally by the presentinvention to use higher carrier frequencies, multiple channels andbi-directional, one-port repetitions, also allows non-carrier or lowfrequency carrier based communication protocols to utilise the presentinvention. As an example, the Ethernet protocol may be modulated ontocarriers in a manner similar to the use of cable modem protocols. LongRange Ethernet is a particularly interesting protocol for use with theinvention because it uses QAM similarly to cable modem systems, Docsisand EuroDocsis. Even PLC protocols and signal formats may be used in asimilar manner. The invention can be used for most communicationsprotocols and modulation types. Proprietary communication protocols andmodulation schemes may be applied. Examples modulation types andcommunication protocols are frequency spread spectrum OFDM, timefrequency spread spectrum DSSS, QAM, QPSK, and protocols like cablemodem DOCSIS and EURODOCSIS, IEEE802.11x, Bluetooth, TETRA, GSM, GPRS,GSM, UMTS, IP telephony and other types of telephony. Depending on therequirements, the signals handled by the invention may be double orsingle side band. Again, being able to use high frequencies whereattenuation in the medium is high attenuates reflections to negligiblelevels, which may be a very important facilitation by the invention.

By facilitating wide bandwidth communication on global infrastructureslike power grids circuits, new concepts for mobile communication andother becomes possible. As an example, the everywhere present powerinfrastructure allows the invention to realise a larger number ofreduced area communication cells at greatly reduced total system costand improved overall coverage. Wherever power cables or wires arepresent, the invention makes it possible to provide backboneinfrastructure for a base station of as an example a UMTS base station.When used as wireless repeaters the invention also makes it possible toextend the radio coverage of base stations at very reasonable costs.

SHORT DESCRIPTION OF THE FIGURES.

The present invention is described in more detail in the following withexamples and references to the appended drawings, where

FIG. 1 shows the block diagram of a typical transponder systemcorresponding to known technology comprised by an analogue and a digitalunit;

FIG. 2 shows a block diagram of an implementation of the first aspect ofthe present invention, where the simplest possible method ofretransmission based on the present invention is shown;

FIG. 3 shows a block diagram of an implementation where a separateoscillator signal is introduced in order to improve control withbandwidth, unwanted radiation and energy consumption of the transponder;

FIG. 4 shows a block diagram of another design version where a detectorand amplification for reception (down link) is arranged and wherevarious levels of reception may be controlled by an introduced TRswitch;

FIG. 5 shows a block diagram of still another design version, where thetransponder is introduced in a microwave ASIC due to the simplicity ofthe microwave technical concept which the present invention is basedupon which again permits simple and low cost realisation in microwaveASIC or a MMIC;

FIG. 6 shows a block diagram of an implementation that diverts from thedesign version in FIG. 2 in that an antenna is replaced by a differentcoupling element as well as a filter in the signal path to and from theoscillator is shown as a split, bi-directional filter;

FIG. 7 shows a block diagram illustrating the second aspect of theinvention where a super regenerative transponder works as part ofnetwork architecture;

FIG. 8 illustrates de various signal transmission mediums that atransponder in a network may be connected to, FIG. 9 shows a specialdesign version a transponder according to the present invention aimed atco-operating with a network;

FIG. 10 show an application of a number of transponders together invarious ways in connection with network solutions;

FIG. 11 shows an application of a number of transponders together instill another embodiment; and

FIG. 12 shows an example of distribution of transponders alongtransmission lines or waveguides to increase capacity of the line.

FIG. 13 shows one method of achieving desired signal dynamics andbandwidth with the regenerative transponder at the same time asisolation between port terminal and the regenerative circuit isimproved.

FIG. 14 shows one method of realising a one-port frequency transposingtransponder or amplifier using conventional techniques which isapplicable to the present invention when sufficient and reliable poweris available as in certain areas of power line communication. FIG. 15shows how bi-directional frequency transposition and one-portbi-directional amplification may be applied to symmetrical communicationsystems like IEEE802.11b. The same principle can be applied toasymmetrical communication using different up and down link frequencybands simply by adding redundancy in the implementation.

FIG. 16 shows how the present invention for asymmetrical communication,i.e. cable modem signals, partly or largely can be realised usingdirectional coupling and frequency transposition. When sufficiency poweris available, large amplification and directional coupling can be usedto sustain signal to noise ratio using higher carrier frequencies oni.e. lossy power lines and cables.

FIG. 17 shows an embodiment of the invention where radiated signals andnoise from an antenna or probe arrangement can be combined with thedirectly coupled signals to cancel radiated signals and common modenoise and interference in a cable and wire based system.

FIG. 18 concerns power grid communication access systems and contain anoverview drawing of a novel type access system facilitated by theinvention. A novel solution for medium voltage stations is shown plus adrawing of a novel solution for applying gain in distribution boxes andother termination points are shown.

FIG. 19 mainly concerns some methods of the invention of how couplersare connected to medium voltage cables, using transformers as acapacitor network to pass high frequencies through the transformer aswell as galvanic, differential couplers with low voltage cables.

DETAILED DESCRIPTION

In FIG. 1 is shown a typical transponder device 18 consisting of ananalogue 22 and a digital 23 unit. The analogue part has an antenna 1and a radio frequency transponder 24. The transponder 24 may be amodulated transmitter or a transponder capable of retransmitting theincoming carrier with a modulated response from the transponder 18. Itis often designed to include a down link receiver 25 and a wake upreceiver 26 as well as a control unit 25. When the digital part isincluded in the transponder device 18 it will consist of an informationunit 28 normally combined with an interface 29. The transponder device18 also consists of a power supply most commonly made up of a battery170.

The most important part of the transponder device 18 is the transponder24 for up link. The down link information receiver 25 is either aseparate part of the transponder device 18 or is partly integrated withthe wake up receiver 26. The digital unit 23 information device 28identifies the transponder device 18 and the digital unit may alsopossess abilities of processing information as well as perform controlof functions in the analogue unit 22 through a control interface 27. Thedigital unit 23 may also contain a physical interface 29 towards user,sensors or actuators.

In FIG. 2 a block diagram of a transponder 19 not including anyinformation unit and according to the present invention is shown andwhere a simple method for retransmission with the help of the presentinvention is illustrated. The solution shown for the present inventionmay be used both for signal repetition, interrogation and transmission.It encompasses a bi-directional coupling 2 between antenna 1 and a bandpass filter 3, and a bi directional coupling 4 being a single or dualsignal path leading to a regenerative circuit 5 that contains separateparts or is integrated in a circuit which, depends on the requirementsof the transponder 19.

The regenerative circuit 5 may in principle contain a random typeoscillator circuit which again is identical to a destabilized amplifier,and the connection point involves in principle any point or points inthe oscillator where the necessary coupling of energy in and out of theregenerative circuit is achieved. This gives a regenerative or superregenerative amplification which is sufficient for the purpose of whichthe transponder is intended. A bias circuit 6 supplies bias tooscillator 5 that may contain a bipolar or field effect transistor intransponders from the short wave ranges and all the way up to the cm andmm wave ranges (microwave). Regenerative circuit 5 will in the case ofan oscillator only consist of one transistor, but may in principleconsist of more, like when resonating elements other than coils andcapacitors are used or it may contain an integrated circuit, i.e. a MMIC(microwave integrated circuit). Likewise the regenerative circuit 5 mayalso consist of a number of oscillators to achieve bandwidth and gain.An electronic control element 7 that may be comprised by a diode ortransistor has two main positions. One gives the oscillation conditionswhile the other quenches the oscillating state. The use of such a switchin connection as shown is called “quenching”. The working principle ofthe transponder in the case of a regenerative oscillator is that thecontrol element never permits the oscillator or oscillators ofregenerative circuit to oscillate continuously.

In FIG. 3 a block diagram is shown with a second example of the presentinvention, with a transponder 19 where separate modulators 87, 17 areintroduced for modulation of information 65 respectively switching 31,to improve control with the transponder 19 bandwidth, unwanted radiationand current consumption. The modulation or quenching function 38 mayalso serve as a local oscillator signal and thus add a second conversionor heterodyne function to the regenerative circuit 5 the purpose beingto allow the bandpass filter 3 to have a frequency pass band differentto that of the regenerative circuit 5. A signal 39 or 67 may be a signalfrom a separate oscillator, processor, phase locked loop (PLL) or asimilar arrangement that is able to generate a high frequency signal, orit may in less critical applications be generated as a self oscillationin the oscillator 5 (self quenching) which also allows simplesynchronizing of the quench action by some function superimposed on thereceived signal 60, 62. Separate modulators for information andswitching makes it possible to use a pulse forming network 9 togetherwith the frequency of the signal 39 and the function of the modulator 17can control various properties of the transponder 19 like shaping of thehigh frequency pass band for the regenerative circuit 5.

FIG. 4 shows a block diagram with the third design version of thetransponder according to the present invention, where a detector 11 isintroduced as well as an amplifier 12 for receiving (down link), wherethe transponder still can be used both for signal repetition,interrogation, transmission and reception. The solution shown includesalso a frequency or level discriminating amplifier 13 for wake up andthe design version also includes a T/R (transmit/receive) switch.

The working principle of reception of information (down link) is that asignal that is connected relatively loosely to the signal path 2, is ledby the help of a coupler 95 to a detector 11 (i.e. a Schottky diode)that demodulates the modulated signal received on the antenna 1 and isamplified by the oscillator 5. The receiving circuit then enjoys theselectivity of the bandpass filter 3 to reduce intermodulationdistortion caused by the output from regenerative circuit 5.

FIG. 5 shows a block diagram of a fourth design version of thetransponder according to the present invention, here shown as an“analogue unit” 120 where the invention is implemented in a microwaveASIC (customer specified integrated circuit) 651 or MMIC (microwaveintegrated circuit). The implementation is comprised by either the radiofrequency transponder 120 only or it contains a digital unit 125 aswell, a clock oscillator 135 and input and output terminals.

FIG. 6 shows an implementation that is fairly similar to the exampleshown in FIG. 2 and may be similar to the examples shown in FIG. 3 andFIG. 4, but it is shown that the antenna 1 is generalised as a couplingelement of a more general type. Moreover is shown a special type filter3, namely with possibilities for differing filter characteristics of thetwo signal paths to achieve a frequency shifted retransmitted signal.This is sometimes known as frequency transposing, transposition orconversion.

FIG. 7 The function generator function may include a secondary quenchingor modulating signal or carrier which will allow the quenched oscillator18, 19, 5, 601-606 to act as a frequency up- or down-converter inaddition to the regenerative amplification. This allows the regenerativefunction to take place in a frequency band which is favourable forachieving the desired quench frequency spacing and dynamic properties,while the communication band may be at any frequency sufficiently spacedfrom the regenerative circuit 5 frequency pass band. Added inputisolation also results from the frequency band differences, input filter3 and selectivity of regenerative device 5, 601-606. Thus, the frequencyup- or down-converted amplified signal out will be in-phase with thesame signal in due to perfect symmetry. External synchronising of thefrequency source is achieved by synchronising to an externalsynchronising signal 31 or by synchronising to the implicit quenchsignal 32 of a corresponding transponder 511 in the network.

FIG. 8 shows, in accordance with FIG. 7, the various mediums andtransmission medium interface methods that the invention offers novelusage of, in particular concerning regenerative cascaded gain,including:

Free space propagation 400 in vacuum, gas, liquids or solid materialwith the help of antennas or probes,

Transmission line 410 consisting of a multi-lead electrical cable orcable like infrastructure, where more than two wires allow differentialtransmission line modes for improved common mode rejection

transmission line 420 consisting of an open, electric line or anarrangement corresponding to an open electric line which contains two ormore conductors and that are twisted or not twisted, metal structurescomprising a transmission line, transmission line or a line systemcomprising a wandering wave antenna line system 430 consisting of on ormore wires and where the transmission wave is referenced to earth, andwhere both differential and single wire excitation is possible. Examplesof wandering wave antennas are the horizontal V, the Rhombic and theBeverage antennas.

transmission line 440 performing as a wave guide with open surface, a socalled Lecher Wire where, the wave when, having a short wavelength, iskept trapped near the wire and experiencing low attenuation and can beexcitated and tapped using known methods, transmission line 450 which,is a closed waveguide and may be resembled by a metal pipe, andtransmission line 460 being an optical waveguide as the transmissionmedium and possibly to serve as a none galvanic connection to anelectric medium.

Connections to lines used in the invention may be realised asdifferential (symmetrical) or asymmetrical couplings with the help ofinductive (magnetic, Hs field) arrangements 141, capacitive arrangement(electric, E-field) 142, resistive arrangement 143 (galvanic coupling)or, a combination of the three as with transmission lines in the form ofmicro strip. The coupling arrangements of the types 141, 142 and 143 mayin some cases be used alone or in combination to power the transpondersfrom the hosting infrastructure. In practice, the non-galvanic couplingsmake take different forms. A novel example of a type of capacitive 142coupling is the capacitive probe connections of “Elastimold” highvoltage power cable terminations in connections with the high signalgains offered by the present invention. Another novel example ofcapacitive coupling 142 in the invention is the use of cable shields asthe coupling capacitor to the inner conductor or conductors of thecable. An “antenna” within a high voltage compartment is still anotherexample of interfacing made possible by the present invention. Forsignal excitation in the invention, the antenna is more efficient as anear field antenna in the form of a magnetic loop 141 which may alsoprovide another novelty of the invention by easily allowing differentialcoupling to two phases of a three phase cable termination. A small, selfpowered transponder placed directly on a high voltage power cabletermination is yet another example of the invention providingnon-galvanic coupling to the outside world or for interconnections ininfrastructures.

According to the invention all couplings to and from different mediumsas shown in FIG. 8 may concern the object of maintaining the signalalong the path in the medium, excitation of the medium or output fromthe medium

FIG. 9 shows a transponder 512 in accordance with FIGS. 7 and 8, wherean output 305, 306 is defined in the regenerative circuit 355 making theport 303, 304 an input or both input and output, while the port 305, 306is an output with a higher level and input with lower sensitivity. Thearrangement should serve to achieve a large dynamic signal by utilisingsignal gain and output level capability of the regenerative circuit 355which possibly also contains a high frequency gain block to for theintended regenerative dynamic range. The ports 303, 304 and 305, 306have arrangements 221, 222 connected for reception and transmission ofsignals for retransmission 71, 81 of information and or reception 72, 82and transmission 71, 81 of information and possibly reception 72, 82 ofsynchronising/locking 72, 82 and possible transmission ofsynchronising/locking 71, 81. The coupling arrangements 221, 222 may beinterconnected with a directional coupler or utilise the isolation ofthe medium to which arrangements 221, 222 are coupled.

FIG. 10 shows an embodiment of the invention where a number oftransponders or regenerative circuits 213 of the synchronised or nonesynchronised type, in order to improve dynamic characteristics ofsignals in one or more directions 150, 151, may be connected together ina coupling arrangement 210 with the help of a common couplingarrangement 90 or with the help of separate coupling arrangements 210,211, 212 having attenuation between them and may constitute variouspoints along a transmission medium or path. Correspondingly anembodiment of the invention is where a number of transponders orregenerative circuits 214, 215, 216 are arranged to increase bandwidthand dynamics and may be connected together to a coupling arrangement 210with the help of a common coupling 90 and thus may constitute a multipole, regenerative band pass filter. According to the use oftransponders or regenerative circuits 213 together with 210, 211, 212that similarly may be used with transponders or regenerative circuits214, 215, 216 that may have differing specifications possibly toaccommodate a number of channels, two-way architectures, differentservices, redundancy or other purposes served by a plurality of channelcharacteristics.

FIG. 11 shows, in accordance with the invention how a number oftransponder units 216, 217, 218 may be connected together with the helpof a common coupling or transmission line 90 allowing the couplingarrangements 210, 222 to transmit signals 161, 162 between a physicalposition 221 and signals 171, 172 on a different physical location 222,for example from one room 221 to another room. The physical locations221, 222 or any number of physical locations may also be in free spaceusing wireless transmissions and can facilitate communication when rangeis excessive or in shadow zones.

FIG. 12 shows a general example wherein the invention provides a novelsolution to transforming a cable or wire grid into an efficient signalnetwork able to accommodate high frequency signals over long distances.Regenerative circuits 219 representing transponders or repeaters aredistributed across the infrastructure grid 91 serving as transmissionlines. Galvanic or none galvanic couplers 121 may be inserted at anysuitable point across the grid as inputs or output of the grid. Withstructures of a closed nature as with shielded cables, transponders 219are most conveniently inserted at existing termination points as indistribution panels and the like. In some cases, using a transponder120, the input, or output or both of the grids may be served by awireless coupling using an antenna arrangement 95. The invention, usingtransponders 219 is also suitable for placement using penetration of forexample a cable, using galvanic or none galvanic coupling.

FIG. 13 shows one example of another embodiment of the present inventionin connection with FIG. 7 where a secondary quench signal achieved anin-phase, bidirectional heterodyne function. The shown implementation ofthe transponder offers added input isolation at the expense of somecomplexity. Desired dynamic properties will only be achieved if thebidirectional frequency converter 750 is arranged to present equal andopposite phase shift in between the port 751 for incoming respectivelyoutgoing signals and the regenerative device 18, 19, 5, 601-606. Thesimplest way to achieve this is using a single diode mixer, i.e. aSchottky diode. Sufficient filtering may be achieved using bandpass,highpass or lowpass filtering 753. Frequency and phase drift in thebi-directional frequency converter 750 will be automatically compensatedwhen the bi-directional symmetry is properly sustained as with a simple,single diode mixer. Where practicable from for instance a frequencystandpoint, more elaborate mixers in the bi-directional converter 750,754 may be used including balanced mixers which will improvecharacteristics. A more detailed description of the frequency converter750 for increased signal dynamics 754 includes separate chains withamplifiers 761, 762 and bandpass filters 759, 760 for input and outputsignals respectively. Amplifiers 761, 762 may compensate for losses inthe mixer circuit 755 and provide necessary output signal levels 757.The mixer circuit 755 may be a single balanced mixer with a localoscillator. Mixer circuit 755 may also contain separate mixers for inputand output signals respectively for added signal chain isolation. Mixercircuit 755 may also contain additional combiner isolation on thebidirectional port 763. The bidirectional bandpass filter 758 greatlyimproves signal dynamics. Input 756 and output 757 may be connected to adirectional combiner to realise a one port transponder or usedseparately where appreciable output to input isolation is available.

FIG. 14 shows an embodiment of the present invention which is a morecostly, complicated and power consuming implementation with a functionprincipally identical to the frequency transposing regenerativetransponder. It consists of input filtering 871, frequency converter752; output filtering 872 and a high gain amplifier 860. The output istied directly or via a directional combiner hybrid to the input 826 topresent a frequency transposing one-port amplifier at the terminals 825.The application hereof may be in power cable or wire systems as well aswireless systems to increase noise tolerance, adaptation to varyingcable types, lengths and losses using one-port amplification including afrequency shift. It may utilize sharp, even loss filters to allow thefrequency converted channel to be adjacent to the input channel. It iswell suited to sustaining the signal to noise ratio on a transmissionline like a power cable without exceeding critical radiation levels. Aswith other super heterodyne solutions, it may be realised as a doubleheterodyne and thus allowing so-called pass band tuning which can becontrolled by a variable oscillator and be easily remote controlled. Theoutput 827 may in stead of being directly tied to the input 826 and acommon point 825 be connected separately to a point 828 in theinfrastructure or communication medium which exhibits some isolation tothe firstly mentioned point 825.

FIG. 15 shows how bi-directional frequency transposition 830-832 andone-port bi-directional amplification 840-842 may be applied tosymmetrical communication signals 801, 802, 803, 804. The transmissionmedium 810 may be a lossy power line cable connected to other mediumsthrough 821, 822, i.e. other cables. The present invention explains thepossibility of using one-port frequency converters 830-832. Frequencyconverters 830-832 may also be multi-port frequency transpositiondevices provided that the transmission medium 810 can be interrupted.Long or large attenuation signal paths can be compensated with anynumber of intermediate devices 831, 841. The same principles can beapplied to asymmetrical communication using different up and down linkfrequency bands simply by adding redundancy in the implementation. Theapplication both for asymmetrical and symmetrical communication systemsmay be in power cable or wire systems as well as wireless systems toincrease noise tolerance, adaptation to varying cable types, lengths andlosses using one-port amplification including a frequency shift. It iswell suited to sustaining the signal to noise ratio on a transmissionline like a power cable without exceeding critical radiation levels.

FIG. 16 shows how the present invention for asymmetrical communication,i.e. cable modem signals, partly or largely can be realised 1010 usingdirectional coupling 950, 951 and selective frequency transposition 910,921 in differing frequency bands. When sufficient power is available,low cost large amplification and directional coupling can be used tosustain signal to noise ratio using higher carrier frequencies on i.e.lossy power lines 810 and cables 810. This embodiment of the invention,due to the various possible connection schemes 1011-1014, overcome atvery low costs the problems of earlier industry attempts to achievelarge bandwidth over great distances. Using high carrier frequencies,efficient coupling and isolation can be accomplished by any of thecoupling schemes 1011-1014 whereas the allowable high gain amplificationcompensates for the high losses at carrier frequency. Frequency bandscan be chosen for the current lossy transmission medium, i.e. powercable and to allow signals in both directions to operated undisturbedand away from low frequency noise as well as benefiting from attenuatedreflections and reduction of group delay ripple. In the first connectionscheme 1011, combined attenuation from directional couplers 935, 936 andbandpass, lowpass or highpass filtering in 1010 allows the common ports935, 936 of the couplers 935, 936 to be tied together and yet achievinguseful gains while attaining unconditional stability. Isolation ports945-946, 955-956 are tied to inputs and outputs 930-931, 940-941 of1010. The medium 915 may be a lossy power cable. Connection scheme 1012shows a similar implementation where the transmission medium allowsinterruption. Connection scheme 1013 uses none galvanic coupling 975,976, 985, 986 to the transmission medium, which may be one or more powerline cables. The couplings 975, 976, 985, 986 can typically be of thecapacitive type 142, i.e. the capacitive test coupling in “Elastimold”power line stations or stray capacitive coupling or “antenna”arrangement within a high voltage power switch cell compartment. Anantenna arrangement in the invention may efficiently take the form of amagnetic loop antenna which also facilitates a novel solution forsymmetrical, differential excitation and tapping of high voltage andmedium voltage cables in particular. A novel approach of fibre opticcable based interface to high and medium voltage cables is fascilitatedby the invention where the regenerative gain block used between the highvoltage and the fibre cable may be optically powered through the fibrecable or by tapping power from the high voltage inductively orcapacitively and at the same time conveniently can provide bidirectionalcapabilities whereas two such arrangements may provide differentialmode. Connection scheme 1014 utilises a combination of schemes1011-1013. This is especially applicable to the transition of two-waysignals between high voltage power cables and low voltage power cables.In this case, connections 985, 986, i.e. at the high voltage side,assist isolation by not being tied together, while connection 965 may berouted to one or more 220 Volts power cables using interconnectingcoaxial cables.

FIG. 17 shows a novel embodiment of the invention radiated signals 1050and noise 1051 from a noise probe arrangement 1120 can be connected viaa combiner 1130 with the directly coupled signals and noise 1105 tocancel radiated signals and noise pick up in a cable 1101 based systemusing a connections scheme 1110 which may be of the types 1011-1014. Thecombiner 1130 may be of an analogue or a digital signal processing typeand allows common mode noise cancellation possibly by automaticadjustments of phase and amplitude relationships to be adjusted 1135 forminimum radiated system signal levels and minimum system noise on anytapping or injecting signal path 1140. The probe arrangement 1120 mayinclude several probes or antennas whereas the H-field probe will bemost efficient for common mode immunity in transformer stations and E-and H-field probes, antennas or emitters may be necessary for plain wavemissions and immunity. FIG. 17 deals with a problem mostly encounteredin power grid old transformer installations. It has less relevance topower grid field distributions that mostly have metal or steel shieldingnot only for screening but for personnel and public safety purposes aswell. _The passive part of the probe or probes 1120 may be constitutedby parts of a cable shield or similar.

FIG. 18 shows different embodiments of the invention and in 595 is anoverview drawing of a novel type access system facilitated by theinvention and which may use one or more of a number of modulation typesand communication protocols and it may for example be cable modem based.The invention facilitates the entire structure of power cables and wiresin a community being used as a communication network through the variousembodiments of the invention allowing cascaded analogue gain,interconnections, bi-directionality and optimal use of the highfrequency capacity of the infrastructure. This includes high 526 tomedium voltage transformer stations 525, medium to low voltagetransformer stations 521, three phase medium voltage shielded groundcables 528, three or single phase low voltage cables 530, 531, 532, 556,medium voltage mast mounted 537 lines 591, low voltage mast mounted 537cables or lines 592, low voltage distribution boxes 529, home fusepanels 533, building main distributions 539 and sub distributions 538,street light masts 528 and cabling 527 and may be combined with fibrering infrastructure 590 using analogue fibre interfaces 536 todistribute 535 signals one or two-way at strategic points of the powergrid infrastructure in a HFC (Hybrid Fibre Coax) manner. Customerpremises equipment (CPE) 534 may be installed in or near the fuse panel.The digital to analogue and analogue to digital equipment (AID-D/A) 524may be installed at any point in the power grid architecture andsometimes most favourably and economically in the high to medium voltagetransformer station 522 where one fibre connection 523 may serve theentire access network. The fibre ring 590 may also distribute digitalsignals to various A/D-D/A 524 equipment at various locations in thesystem when this is economical. In FIG. 18, 596 an embodiment of theinvention shows how signals may bypass the transformer 521 in a mediumvoltage transformer station 596. Unidirectional or bidirectionalregenerative repeaters 548 according to the invention provide necessaryand stable signal gain as well as multi channel capability passed thetransformer between any number of couplings, preferably of thedifferential kind which may be in the form of baluns, 543 and 554 in themedium voltage compartments 544 and the low voltage distribution 553,respectively. The rails 544 with any switching arrangement may be of theopen type, shielded type or the Elastimold or similar type. Accordingly,597 is another embodiment of the invention where regenerative gain 561and connectibility 559, 565 may be applied to a connection box,distribution panel or any other cable termination point to provide ahigh quality analogue signal path, unidirectional and bidirectionalbetween point 557 and points 566. This solution adds the inherent,limited high frequency isolation always present through straps, fuses orother 564 and rail 563 and provides stable gain through the regenerativeanalogue gain in 561.

FIG. 19 concerns various embodiments of the invention of passing highfrequency signals to and from a medium voltage or high voltage cable inconjunction with applying analogue gain in a power grid communicationsystem consisting of various voltage levels and utilising the cascadingof cables of different voltages. An equivalent diagram of an Elastimoldor similar system voltage probe point is shown 635 which may be used inthe invention, especially as a signal sensor point. A suitable network638 may be used in conjunction with the probe point 635 or signals maybe tapped directly into a high impedance preamplifier. Excitation may beperformed more efficiently using stray capacitances on high frequencieswith the embodiment of the invention-in 637. The cable 581 may beterminated in a transformer 577 where intrinsic, efficient straycapacitances for high frequencies exist between centre conductor 581 andthe high frequency common potential 578 or it may utilise straycapacitance between the cable shield and the inner conductor at thetermination end of the cable. This allows excitation or even tapping totake place between the a capacitor sleeve clamped on the cable 582, 583and the safety grounding wire 586 of the cable shield using a twoterminal coupler 584 which is connected to the rest of the signal pathof the installation. A toroid core clamped on the cable 579 may improvethe principle. The coupler 584 may also be connected similarly viawindings on the toroid 579. This toroid may also be clamped on thegrounding wire associated with the termination of the cable shield 580or toroids may be used in both places. In a three phase installation 636two cables 574-576, may be used separately for increased capacity or inpairs for differential modes. The coupler 584 may also be connectedbetween the cable shield safety grounding wire point 586 and the highfrequency common potential 587 in stead of using a sleeve 582 and atoroid may be clamped on the mentioned grounding wire and the couplermay also be connected to windings on the lastly mentioned toroid and inthis way utilising the intrinsic stray capacitance to the commonpotential in the transformer 577. Stray capacitances within thetransformer 640, 641 may also be used as coupling networks to pass ahigh frequency signal through the transformer, possibly using matchingnetwork similar to the kind in 638. A high frequency signal may also bepassed though a transformer 642 by using the impedance or increasing theimpedance 630 between the neutral terminal of the transformer 624 andground and connecting a coupler 633 across this impedance. An embodimentof the invention 643 which does not allow differential mode but whichstill is useful in medium an high voltage compartments that are wellshielded and exhibits low noise utilises intrinsic stray capacitances655. It may also utilise introduced stray capacitances 666. Seriesimpedances, possibly in the form of clamp on magnetic materials may beintroduces 659 to reduce influence from low loss open rails 657. Thestray capacitances allow excitation and tapping through a coupler 664connected between the cable shield grounding 662 and the cable shieldand the grounding high frequency impedance 659 may be increase usingclamp on magnetic material. The high frequency energy is then coupled tothe cable at the shield and at the inner conductors via the straycapacitances 655, 666. Galvanic coupling to two and three phase lowvoltage cables as shown generally in FIG. 18 may use differential modeas in the embodiment of the invention 647 through a coupler 683 whichmay contain one or more baluns using a pair of the phases 685 of the lowvoltage cable 670 and clamp on magnetic material 659 may be used toappreciably increase isolation to the low voltage rail or any othertermination devices which the cable is connected to.

1. Transponder for amplification of a received signal (60) into areceiving element (1), e.g. an antenna, to a signal (61) forretransmission, where the retransmission signal (61) possible can haveinformation superimposed, characterized in that the transpondercomprises, as an amplifying element, a quenched oscillator (5). 2.Transponder according to claim 1, characterized in that the oscillator(5) is a superregenerative oscillator.
 3. Transponder according to claim1, characterized in that the oscillator (5) exhibits negative resistance(30) for the received signal (60).
 4. Transponder according to claim 1,characterized in that the oscillator (5) is connected to a quench switch(7) arranged for coupling a quench signal (31) into the oscillator. 5.Transponder according to claim 1, characterized in that the oscillator(5) is operative to deliver the retransmission signal (61) onto the samesignal path (2, 3, 4) as the path followed by the received signal (60)from the receiving element (1), which signal path (2, 3, 4) thus isbi-directional.
 6. Transponder according to claim 1, characterized inthat the oscillator (5) comprises a resonator element of any type, butwith a Q factor suitable to give the retransmission signal (61) large tovery large amplification.
 7. Transponder according to claim 4,characterized in that the quench switch (7) is arranged to switch a biasvoltage (6) to the oscillator (5).
 8. Transponder according to claim 4,characterized in that the quench switch (7) is operative to switch inand out an impedance that the oscillator (5) sees.
 9. Transponderaccording to claim 4, characterized by a modulator (17) which controlsthe quench switch (7) with a switching signal (32).
 10. Transponderaccording to claim 5, characterized in that the bi-directional signalpath (2, 3, 4) between the antenna (1) and the oscillator (5) hasadditionally a band pass filter (3) included.
 11. Transponder accordingto claim 9, characterized in that the modulator (17) is operative toreceive a modulator signal (63), which may be a information carryingsignal, and to produce the switching signal (32) as a function of themodulator signal (63) whereby the quench signal (31) leads tosuperimposing of a modulation signal on the retransmission signal (61).12. Transponder according to claim 9, characterized in that theoscillator (5) is connected to an additional modulator (87) forsubmission of an information signal (38) to the oscillator (5)independently of the quench switch (7) and the firstly mentionedmodulator (17), said information signal (38) being generated by theadditional modulator (87) on the basis of an additional modulationsignal (63) which contains the information.
 13. Transponder according toclaim 12, characterized in that the switching signal (32) is apredetermined frequency that is from higher to many times higher thanthe highest frequency component of the information signal (38). 14.Transponder according to claim 9, characterized by the inclusion of atleast one transmit-receive switch (14) connected to at least one of abias arrangement (6) for the oscillator (5), a modulator (17, 87) and apulse forming network (9) for the switching signal (39, 32), for controlof switching signal and bias voltage.
 15. Transponder according to claim10, characterized by further having included a detector arrangement(11), like a Schottky diode, coupled high frequency-wise to theoscillator (5), preferably loosely coupled to the signal path (4) closeto the oscillator (5), using a coupler (95), in such a way that theinformation carrying received signal (62) can be amplified by theoscillator (5) in order to increase the amplitude of a detected signal(33, 34) behind the detector arrangement (11).
 16. Transponder accordingto claim 15, characterized by the inclusion of an amplifier (12)connected following the detector (11), for amplification and possiblyfiltering of the detected signal (33) into an infosignal (36) of desiredamplitude and dynamic properties.
 17. Transponder according to claim 15,characterized by the inclusion of a wake up circuit (13) connectedfollowing the detector (11), for utilisation of the detected signal (34)to produce a wake up signal (37).
 18. Transponder according to claim 10,characterized in that the band pass filter (3) in operative to filterout all side bands that result from the quench signal (31) frequency, toallow the retransmitted signal (61) to become a clean, amplified versionof the received signal (60) thereby acheving an analogue relay link. 19.Transponder according to claim 10, characterized in that the band passfilter (3) is bi-directionally divided and encompasses two directionalfilters, in order to achieve a retransmission signal with frequencyshift.
 20. Transponder according to claim 9 and 10, characterized byintegrating at least two of the transponder elements hereby stated:receiving element (1), band pass filter (3), further signal path (2, 4),oscillator (5), quench switch (7) and modulator (17).
 21. Transponderaccording to claim 1, characterized by being implemented as a customerspecified, integrated circuit (ASIC, 651) with analogue circuits (120).22. Transponder according to claim 21, characterized in that the ASICcircuit (651) also incorporates digital modules (125, 135). 23.Transponder according to claim 21, characterized by the ASIC circuitincorporating a duplex transceiver with or without frequencytransposing.
 24. Transponder according to claim 1, characterized in thatit is implemented as a microwave integrated circuit (MMIC, 651) usinganalogue circuits (120).
 25. Transponder according to claim 1,characterized in that the receiving element (1) is implemented as acoupling or probe to a transmission medium like a transmission line. 26.Transponder according to claim 1, characterized in that the oscillator(5) is operative as a two port with an input and an output where theinput is a signal sensitive point in the oscillator like a transistorbase, gate, source or emitter, while the output is a point where highestpossible energy level may be collected, like a transistor collector,drain, emitter or source.
 27. Transponder according to claim 26,characterized in that the twoport being coupled to an arrangement fordirectional attenuation, to utilize the total dynamic range of thetransponder.
 28. Transponder according to claim 26, characterized inthat the twoport is coupled to separate receiving elements andtransmission elements.
 29. Transponder according to claim 1,characterized by a filter arranged to reduce harmonic overtones from theoscillator (5) quench frequency in the frequency range where thetransponder sensitivity is largest, which filter is part of theoscillator or is a part (8) of a separate circuit connected to theoscillator (5).
 30. Transponder according to claim 1, characterized byan arrangement (87) for introducing secondary quenching as oscillationssuperimposed on the primary quench oscillation, at a point in theoscillator (5) where the oscillating conditions can be influenced. 31.Transponder according to claim 1, characterized by a function generator(9) for asymmetrical control of the quench oscillation.
 32. Use of atleast one transponder in accordance with claim 1, in a wireless orwire-based network, the receiving elements (1) of the transponders beingimplemented as couplings or probes (141, 142, 143, 223) to networktransmission mediums (92, 400, 460) like for instance transmission lines(410, 460).
 33. Transponder system for wireless and wire-based networks,comprising a number of transponders (19, 601, 606, 213, 219) foramplification of a received signal (60) into a receiving element (1,141, 143, 200, 220, 223), for instance an antenna or a probe, to asignal (61) for retransmission, where the retransmitted signal (61) mayhave information superimposed, whereby the transponders can work asintelligent or unintelligent connections in a network based ontransmission through at least one of a number of possible transmissionmedia (92, 400, 460), characterized in that each transponder comprises,as amplifying element, a quenched oscillator (5, 355).
 34. Transpondersystem according to claim 33, characterized in that at least one of theoscillators (5, 355) is of the superregenerative type.
 35. Transpondersystem according to claim 33, characterized in that at least one of thetransponders is a multi-port transponder.
 36. Transponder systemaccording to claim 33, characterized in that at least one of thetransponders is operative to receive a quench signal from a dedicatedquench generator (210).
 37. Transponder system according to claim 33,characterized in that at least two of the transponders are operative toreceive a quench signal from a common quench generator (210). 38.Transponder system according to claim 33, characterized in that at leasttwo of the transponders are operative to receive a control signal forsynchronisation of own quench generator (210)
 39. Transponder systemaccording to claim 33, characterized in that at least one transponder iscoupled to the network with the help of only one coupling element, whichcoupling element is identical to the receiving element.
 40. Transpondersystem according to claim 39, characterized in that the coupling elementis an antenna or a probe in vacuum, gas or matter.
 41. Transpondersystem according to claim 39, characterized in that the coupling elementis made up of a loose coupling to a line, in the form of an inductive,capacitive or resistive coupling, possibly a combination thereof. 42.Transponder system according to claim 35, characterized in that at leastone transponder is coupled to the network using two coupling elements,of which one is the receiving element connected to a first port of thetransponder, and the second is a transmission element tied to a secondport of the transponder.
 43. Transponder system according to claim 42,characterized in that at least one of the coupling elements is comprisedof an antenna in vacuum, gas or matter, a probe in vacuum, gas or matterand a loose coupling to a line, in the form of an inductive, capacitiveor resistive coupling, potentially a combination of these. 44.Transponder system according to claim 33, characterized in that at leasttwo oscillators or transponders are arranged inter-coupled, with commonquenching, or synchronised quenching with controlled phase shiftingbetween different quench signals, to achieve a long active cycle (dutycycle) for the transponder circuit.
 45. Transponder system according toclaim 33, characterized by being incorporated in a wireless orwire-based network based on at least one type of spread spectrumtechnology.
 46. Transponder system according to claim 33, characterizedin that the wireless or wire-based network that encompasses thetransponder system, is based on transfer protocols in accordance with,or based on at least one of the communication systems UMTS, GSM, GPRS,TETRA, Ethernet including Long Range Ethernet, Bluetooth, wireless LAN,satellite access return channels, DOCSIS, EURODOCSIS and other cablemodem protocols.
 47. Transponder system according to claim 33,characterized in that at least one of the transponders is powered via aninductive, capacitive or resistive coupling or a combination of thesecoupling types, from the transmission medium (410, 460) in question. 48.Transponder system according to claim 33, characterized in that theoscillator (5) is a quenched oscillator exhibiting CW oscillation. 49.Use of a transponder system according to claim 33, in an asymmetricalcommunication system, as cable modems, whereby the communication systemmay use transmission medias other than coaxial cables.
 50. Use of atleast one transponder according to claim 1, in a radio positioningscenario using any type of positioning principle, in order to, with theaid of the transponder (19, 219), establish any geometrical place in thepositioning scenario.
 51. Transponder according to claim 1,characterized in that a bi-directional frequency converter (750) isarranged to provide equal and opposite phase shift in between incomingrespectively outgoing signal port (751) and the oscillator (18, 19, 5,601-606).
 52. Transponder according to claim 51, characterized in thatsaid frequency converter (750) is a single diode mixer, for instance aSchottky diode.
 53. Transponder according to claim 51, characterized inthat a bandpass filter (753) is arranged in series with said converter(750).
 54. Transponder according to claim 1, characterized in that aseries connection of an input filter (871), a frequency converter (752)and an output filter (872) is connected between an input terminal (825)and said oscillator (860), an output from said oscillator being tied tothe input terminal (825) thereby to provide a frequency transposingone-port amplifier.
 55. Transponder system according to claim 33,characterized in that the transponders (830, 831, 832; 840, 841, 842)contain bidirectional frequency converters (750) or one-portbidirectional amplifier systems (825, 871, 752, 872, 860). 56.Transponder system according to claim 33, characterized in that thetransponders (910, 920; 911, 921) are inserted between directionalcouplers (950, 951) in an asymmetrical communication system, providingselective frequency transpositioning by means of frequency converters(910, 911).
 57. Transponder system according to claim 33, characterizedb y at least one combiner (1130) for cancelling radiated signals andnoise pick up from signals received from said at least one transmissionmedium (1101), said combiner (1130) being connected to receive signals(1105) and noise from said transmission medium (1101) via a transpondercoupling (1110), and to receive radiated signals (1050) and noise (1051)via an antenna or probe (1120).
 58. Transponder system according toclaim 57, characterized in that said combiner (1130) comprises anarrangement (1135) for adjusting phase and amplitude relationshipsbetween received signals.